The invention relates to a sewing machine, and more particularly relates to a feed dog dropping system of the sewing machine which is operated to displace the feed dog from an upper operative position to a lower inoperative position and vice versa in dependence upon a selected stitch pattern. The same applicant's copending U.S. patent application Ser. No. 6,685, now U.S. Pat. No. 4,236,469, dated Dec. 2, 1980 discloses a similar system including an electromagnetic device such as a solenoid which is energized to connect a feed control pulse motor to a transmission linkage operatively connected to a plunger device which is operated to displace the feed dog from the upper operative position to the lower inoperative position.
Such a prior art requires a considerably large sized solenoid for a limited space of the machine housing and makes the structure considerably complex, and moreover such a system is costly.